1. Field of the Invention
The present invention relates to an anti-inflammatory agent in which colominic acid, a partial hydrolysis product of colominic acid or a pharmaceutically acceptable salt thereof is contained as the effective component. In particular, the present invention relates to a therapeutic drug for renal diseases, a therapeutic drug for hepatitis, an immunomodulator and a drug for inhibition of chemotaxis of neutrophil, in which colominic acid, a partial hydrolysis product of colominic acid or a pharmaceutically acceptable salt thereof is contained as the effective component.
2. Description of the Related Art
Colominic acid is a homopolymer with a molecular weight of about 10,000 and is constituted with sialic acid (N-acetylneuraminic acid represented by NeuAc), and is a polysaccharide which is used as the standard for classification of the seratype of E. coli, Meningitis diplococcus and the like.
Colominic acid is prepared by culturing a microorganism such as a microorganism of Escherichia (see Japanese Patent Publication (JP-B-) (KOKOKU) No. 47-26319, Japanese Patent Disclosure (JP-A-) (KOKAI) No. 1-144989). Oligomers with the molecular weight smaller than that of colominic acid are obtained by partial hydrolysis of colominic acid (see H. Nomoto et al, Arch. Biochem. Biophys., vol. 218, pages 335-341(1982)).
However, the physiological activity of colominic acid and partial hydrolysis products thereof has not been studied in detail. It has been reported that N-acetylneuraminic acid which is a component unit of colominic acid exhibits an anti-virus action, an anti-inflammatory action and an anti-allergy action (See (a) Hirsch, R. L., The Journal of Immunology, Vol. 127, No. 5 (1981) pages 1740-1743, (b) Gorog, P., Agents and Actions, Vol. 8, No. 5 (1978) pages 543-545, (c) Hiromi Ito et al, Japanese Pharmacology & Therapeutics, Vol. 13, No. 7 (1985) pages 479-494, (d) Kai, H. et al, Journal of Pharmacy and Pharmacology, Vol. 42 (1990) pages 773-777.)